var table = document.getElementsByTagName("table")[0];

    //遍歷列
    for (var i = 0; i < table.rows[0].cells.length; i++) {
        console.log(table.rows[0].cells[i].innerText);
        if (!table.rows[0].cells[i].innerText) { }
    }
   

    //遍歷行
    for (var i = 0; i < table.rows.length; i++) {
        
 
var row = table.rows[i];
        console.log(row.cells[0].innerText);
    }

js 遍歷行和列